Heating apparatus in cabin

ABSTRACT

A cabin heating apparatus in accordance with the present invention is provided with a central duct (3) extended to one side of an operator&#39;s seat through a front-to-rear changeover damper (2) connected to an air conditioner unit (1), a rear duct (4) extended to the rear of the operator&#39;s seat through the front-to-rear changeover damper 2 and outlets (9) formed at an extreme end part of the rear duct (4). The cabin heating apparatus is further provided with a lower outlet (6) for supplying an air flow along a floor through an above-to-below changeover damper (5) connected to an extreme end part of the central duct (3), a front duct (7) rising from the above-to-below changeover damper 6 and a front outlet (8) provided at an extreme end part of the front duct (7). An appropriate air flow distribution ratio is set by these changeover dampers (2, 5).

FIELD OF THE INVENTION

The present invention relates to a heating apparatus for use in a cabinof a construction machine or the like.

BACKGROUND OF THE INVENTION

In a cabin of a construction machine, farm machine, industrial vehicleor the like or an automobile, a blower type heating apparatus isprovided to make a comfortable environmental condition for an operatoror driver in winter. For example, a heating apparatus to be installed ina cabin of a construction machine is such that, as shown in FIG. 3, aheater 12 is installed on a floor behind the operator's seat 11 tointroduce air from the cabin through both sides of the heater 12, toheat air in the heater 12 and to supply heated air from the front sideof the heater and, as shown in FIG. 4, an air conditioner unit 1 isinstalled on a floor behind the operator's seat to introduce air fromthe cabin through an inlet 13, to heat it in the air conditioner unit 1and to supply heated air to the front side of the operator's seat 11through a space below the operator's seat and to the upper corner of thecabin from the rear side of the operator's seat 11.

In case of a cabin heating apparatus as shown in FIG. 3, however, heatedair outlets are provided only at the front side of the heater 12, andtherefore the heated air is immediately collected at the upper part ofthe cabin and a temperature distribution in the cabin is not likely toattain an optimum condition such as a head-cool and feet-warmenvironment. Also in case of an air conditioner unit as shown in FIG. 4,the environmental condition in the cabin is similar to the above and theair conditioner unit is unlikely to provide such head-cool and feet-warmcondition even though the heated air is blown out upwardly from theheated air outlets behind the operator's seat 11 to promote aircirculation in the cabin. Such conventional heating apparatuses asdescribed above also have a problem that the operator or driver cannotbe relieved from a feeling of coldness at the front part, particularlythe parts below the knees, of his body.

An object of the present invention made in view of the aboveconventional problems is to provide a cabin heating apparatus capable ofobtaining an optimum temperature distribution even under winterenvironmental conditions.

SUMMARY OF THE INVENTION

A cabin heating apparatus in accordance with the present invention isprovided with a central duct extended to the side of the operator's seatthrough a front-to-rear changeover damper connected to an airconditioner unit, a rear duct extended to the rear of the operator'sseat through the front-to-rear changeover damper and outlets formed atthe extreme end part of the rear duct. The heating apparatus is furtherprovided with a lower outlet for supplying an air flow along the floorthrough an above-to-below changeover damper connected to the extreme endpart of the central duct, a front duct rising from the above-to-belowchangeover damper and a front outlet provided at the extreme end part ofthe front duct.

In use for heating, an air flow distribution ratio by means of thefront-to-rear damper is determined to be`front:rear`=0.95˜0.85:0.05˜0.15 and that by means of the above-to-belowdamper to be `above:below`=0.25˜0.35:0.75 ˜0.65. The air flowdistribution ratios by means of these front-to-rear damper andabove-to-below damper are variable within the ranges shown above or canbe fixed to specific values within the above ranges.

According to the construction as described above, the heated air flowsupplied from the air conditioner unit is divided into optimum air flowratios through two changeover dampers and therefore an air flow suppliedto the feet of the operator is approximately 63% of the overall heatedair flow. When an air flow supplied downwardly from the front outlet isadded to the above air flow, as much as approximately 90% of the overallheated air flow forms an air flow which can surround the feet of theoperator. The operator's feet and the cabin floor are continuouslyheated by such heated air flow and therefore the temperaturedistribution in the cabin can be maintained at an ideal level whichallows the head-cool and feet-warm environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration showing a layout of changeover dampers, ductsand heated air outlets of a cabin heating apparatus in accordance withthe present invention;

FIG. 2 is a comparative graph showing a temperature distribution in acabin with the inventive embodiment of FIG. 1 (broken line) versus atemperature distribution in the cabin with the conventional system ofFIG. 3 (solid line);

FIG. 3 is an illustration of a cabin heating apparatus in which aconventional heater is installed; and

FIG. 4 is an illustration of a cabin heating apparatus in which aconventional air conditioner is installed.

BEST FORM OF EMBODIMENT OF THE INVENTION

An embodiment of a cabin heating apparatus in accordance with thepresent invention is described in detail, referring to the accompanyingdrawings:

In FIG. 1, an air conditioner 1 is installed on the floor behind theoperator's seat and a front-to-rear changeover damper 2 is connected tothis air conditioner 1. A central duct 3 and a rear duct 4 are connectedto the outlet of the front-to-rear changeover damper 2 and the centralduct 3 is connected to an above-to-below changeover damper 5 installedon the floor at the front right side of the operator's seat through theright underside of the operator's seat. A lower outlet 6 is connected tothe front part of this above-to-below changeover damper 5, and a frontoutlet 8 is connected to the upper end of a front duct 7 which risesvertically from the above-to-below changeover damper 5.

The rear duct 4 connected to the outlet of the front-to-rear changeoverdamper 2 is branched at its halfway position and the branched ducts arerespectively connected to two rear outlets 9, 9 provided behind theoperator's seat. The air flow direction of the lower outlet 6, the frontoutlet 8, and the rear outlets 9, 9 can be changed.

For a cabin heating apparatus which is constructed as described above,an air flow distribution ratio by means of the front-to-rear changeoverdamper 2 is set to `front:rear`=0.95˜0.85:0.05˜0.15 and the air flowdistribution ratio by means of the above-to-below changeover damper 5 isset to `above:below`=0 25˜0.35:0.75˜0.65. In other words, the air flowslantly supplied from the lower outlet 6 toward the operator's feet isapproximately 63% which accounts for the greater part of the overall airflow. In addition, the heated air is blown to the operator's lowerextremities from his knees to his feet by facing the front outlet 8downwardly and accordingly approximately 90% of the overall air flow issupplied to the operator's lower extremities.

The air flow distribution ratio can be varied or adjusted within theabove described ranges or can be fixed to specific values and not beadjusted. The air flow distribution ratio is varied by increasing ordecreasing the passage areas of the front-to-rear changeover damper 2and the above-to-below changeover damper 5 through a wire cable 10 whichis actuated by the operator with an air flow adjust lever which is notshown.

FIG. 2 is a comparative graph showing the temperature distribution inthe cabin with the cabin heating apparatus in accordance with thisembodiment and with a conventional cabin heating apparatus. Thetemperature in the cabin was measured at four positions, that is, at thehead, chest, waist and feet of an operator who stayed in a cabininstalled in a testing room. As a result of measurement at temperaturesin the testing room which are set at 0° C. and 10° C. as two standardtemperature levels, a local temperature with the heater shown in FIG. 3(solid line) is highest at the operator's head with respect to bothtemperature levels and lowest at his feet. On the contrary, in case ofthis embodiment (broken line), the local temperature is highest at thefeet and equal at his other three parts with an ideal temperaturedistribution which allows the head-cool and feet-warm environment. Fromthe results of measurements, it is known that, though the localtemperature in the cabin exceeds 25° C., a comfortable temperature canbe maintained in the cabin by appropriately adjusting the airconditioner.

INDUSTRIAL APPLICABILITY

The present invention provides a cabin heating apparatus, useful forconstruction machines and other vehicles, which is capable of ensuringan ideal temperature distribution which allows a head-cool and feet-warmenvironment in the cabin, contributing to improvement of operationefficiency in a comfortable working environment. The heating apparatuscan also apply to a small room or space such as a reading room, personalcomputer room, etc. In addition, the apparatus can be used as an airconditioner by appropriately setting the air flow distribution ratio forfront-to-rear and above-to-below directions.

We claim:
 1. A cabin heating apparatus provided with a central ducthaving a front end part extended to one side of an operator's seat, saidcentral duct being connected through a front-to-rear changeover damperto an air conditioner unit, a rear duct having an extreme end partextended to the rear of the operator's seat, said rear duct beingconnected through the front-to-rear changeover damper to said airconditioner unit, and outlets formed at said extreme end part of therear duct, and further provided with a lower outlet for supplying an airflow along a floor through an above-to-below changeover damper connectedto the front end part of the central duct, a front duct having an upperend part and rising from the above-to-below changeover damper, and afront outlet provided at said upper end part of the front duct, wherebythe front-to-rear changeover damper divides air flow supplied from theair conditioner unit into a flow through said central duct and a flowthrough said rear duct, and the above-to-below changeover damper dividesair flow from said central duct into a flow through said front outletand a flow through said lower outlet.
 2. A cabin heating apparatusprovided with a central duct having a front end part extended to oneside of an operator's seat, said central duct being connected through afront-to-rear changeover damper to an air conditioner unit, a rear ducthaving an extreme end part extended to the rear of the operator's seat,said rear duct being connected through the front-to-rear changeoverdamper to said air conditioner unit, and outlets formed at said extremeend part of the rear duct, and further provided with a lower outlet forsupplying an air flow along a floor through an above-to-below changeoverdamper connected to said front end part of the central duct, a frontduct having an upper end part and rising from the above-to-belowchangeover damper, and a front outlet provided at an extreme end part ofthe front duct, wherein, for use in heating, an air flow distributionratio by means of said front-to-rear changeover damper is determined tobe `front:rear`=0.95˜0.85:0.05˜0.15 and an air flow distribution ratioby means of said above-to-below changeover damper is determined to be`above:below`=0.25˜0.35:0.75˜0.65.
 3. A cabin heating apparatus inaccordance with claim 2, wherein the air flow distribution ratio bymeans of said front-to-rear changeover damper and the air flowdistribution ratio by said above-to-below changeover damper are variablewithin the above described ranges.
 4. A cabin heating apparatus inaccordance with claim 2, wherein the air flow distribution ratio bymeans of said front-to-rear changeover damper and the air flowdistribution ratio by said above-to-below changeover damper are fixed tospecific values within the above described ranges.
 5. Apparatus forheating a cabin containing an operator's seat and a cabin floor, saidapparatus comprising:a heater having at least one air inlet and a heatedair outlet; a front-to-rear changeover damper connected to the heatedair outlet of said heater and having an outlet; a rear duct connected tothe outlet of said front-to-rear changeover damper and having an endpart extending to the rear of the operator's seat, with the end part ofthe rear duct having at least one outlet opening; an above-to-belowchangeover damper positioned at one side of the operator's seat andhaving a lower outlet for supplying an air flow along the cabin floor; acentral duct extending along one side of the operator's seat andconnected from the outlet of said front-to-rear changeover damper tosaid above-to-below changeover damper; a front duct connected to andextending upwardly from said above-to-below changeover damper and havingan end part with a front outlet opening, whereby the front-to-rearchangeover damper divides air flow supplied from the heated air outletinto a flow through the central duct and a flow through the rear duct,and the above-to-below changeover damper divides air flow from thecentral duct into a flow through the front outlet opening and a flowthrough the lower outlet.
 6. Apparatus in accordance with claim 5,wherein said heater is installed on the cabin floor behind theoperator's seat.
 7. Apparatus in accordance with claim 5, wherein saidabove-to-below changeover damper is installed at the front right side ofthe operator's seat.
 8. Apparatus in accordance with claim 5, whereinsaid rear duct has at least two branches, with each branch having anoutlet opening positioned behind the operator's seat.
 9. Apparatus inaccordance with claim 5, wherein said lower outlet is positioned todirect air flow towards the operator's feet.
 10. Apparatus in accordancewith claim 5, wherein said front outlet opening is positioned to directair flow toward the operator's lower extremities.
 11. Apparatus inaccordance with claim 5, wherein the ratio of the air flow from saidfront-to-rear changeover damper through said central duct to the airflow from said front-to-rear changeover damper through said rear duct isin the range of 0.95:0.05 to 0.85:0.15.
 12. Apparatus for heating acabin containing an operator's seat and a cabin floor, said apparatuscomprising:a heater having at least one air inlet and a heated airoutlet; a front-to-rear changeover damper connected to the heated airoutlet of said heater and having an outlet; a rear duct connected to theoutlet of said front-to-rear changeover damper and having an end partextending to the rear of the operator's seat, with the end part of therear duct having at least one outlet opening; an above-to-belowchangeover damper positioned at one side of the operator's seat andhaving a lower outlet for supplying an air flow along the cabin floor; acentral duct extending along one side of the operator's seat andconnected from the outlet of said front-to-rear changeover damper tosaid above-to-below changeover damper; a front duct connected to andextending upwardly from said above-to-below changeover damper and havingan end part with a front outlet opening, wherein the ratio of the airflow from said above-to-below changeover damper through said front ductto the air flow from said above-to-below changeover damper through saidlower opening is in the range of 0.25:0.75 to 0.35:0.65.
 13. Apparatusin accordance with claim 12, wherein the ratio of the air flow from saidfront-to-rear changeover damper through said central duct to the airflow from said front-to-rear changeover damper through said rear duct isin the range of 0.95:0.05 to 0.85:0.15.
 14. Apparatus in accordance withclaim 13, wherein said heater is installed on the cabin floor behind theoperator's seat.
 15. Apparatus in accordance with claim 14, wherein saidabove-to-below changeover damper is installed at the front right side ofthe operator's seat.
 16. Apparatus in accordance with claim 15, whereinsaid rear duct has at least two branches, with each branch having anoutlet opening positioned behind the operator's seat.
 17. Apparatus inaccordance with claim 16, wherein said lower outlet is positioned todirect air flow towards the operator's feet.
 18. Apparatus in accordancewith claim 17, wherein said front outlet opening is positioned to directair flow toward the operator's lower extremities.
 19. Apparatus inaccordance with claim 18, further comprising means for varying the ratioof the air flow from said front-to-rear changeover damper through saidcentral duct to the air flow from said front-to-rear changeover damperthrough said rear duct.
 20. Apparatus in accordance with claim 19,further comprising means for varying the ratio of the air flow from saidabove-to-below changeover damper through said front duct to the air flowfrom said above-to-below changeover damper through said lower opening.